Problem: Khan.scratchpad.disable(); For every level Tiffany completes in her favorite game, she earns $800$ points. Tiffany already has $290$ points in the game and wants to end up with at least $3180$ points before she goes to bed. What is the minimum number of complete levels that Tiffany needs to complete to reach her goal?
To solve this, let's set up an expression to show how many points Tiffany will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Tiffany wants to have at least $3180$ points before going to bed, we can set up an inequality. Number of points $\geq 3180$ Levels completed $\times$ Points per level $+$ Starting points $\geq 3180$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 800 + 290 \geq 3180$ $ x \cdot 800 \geq 3180 - 290 $ $ x \cdot 800 \geq 2890 $ $x \geq \dfrac{2890}{800} \approx 3.61$ Since Tiffany won't get points unless she completes the entire level, we round $3.61$ up to $4$ Tiffany must complete at least 4 levels.